Evaluation of reference intervals for immunoglobulins in children using indirect methods

Area of Science:

• Clinical Chemistry
• Immunology
• Pediatric Diagnostics

Background:

• Accurate pediatric reference intervals are crucial for diagnosing immunoglobulin deficiencies.
• Previous studies, like the CALIPER initiative, established direct measurement-based intervals.
• The immunonephelometric method offers an alternative approach for immunoglobulin quantification.

Purpose of the Study:

• To determine pediatric reference intervals for immunoglobulin G (IgG), IgA, IgM, and IgE using immunonephelometry.
• To validate these intervals against the CALIPER study's findings.
• To assess the impact of outlier exclusion on reference interval calculations.

Main Methods:

• Analysis of 120,194 immunoglobulin results (IgG, IgA, IgM, IgE) from 2020-2023.
• Application of exclusion criteria and partitioning by age and sex.
• Calculation of reference intervals using refineR and kosmic algorithms, with and without outlier exclusion.

Main Results:

• Sex differences were noted for IgM in infants (1 month-1 year).
• IgE showed higher pathologic results in children aged 1-18 years, irrespective of outlier exclusion.
• Reference intervals from kosmic and refineR were largely consistent, with minor discrepancies for IgA and IgE in specific age groups.

Conclusions:

• The study successfully verified CALIPER pediatric reference intervals for IgG, IgA, IgM, and IgE using immunonephelometry.
• The findings support the use of immunonephelometry for establishing reliable pediatric immunoglobulin reference ranges.
• This verification aids in accurate clinical interpretation of immunoglobulin levels in pediatric patients.